Arrow Basics: Parts of a Carbon Hunting Arrow
Bowhunters tend to focus on their bow and its accessories when it comes to choosing equipment. That’s natural after all the bow is the biggest, most expensive piece that contributes the most to the accurate, effective, and reliable shooting.
But the bow is only half of the equation, and the other half is the arrow. If you haven’t optimized your setup by choosing the appropriate arrows, then you have significantly lessened the effectiveness of your bow.
The modern hunting arrow is a far cry from what our indigenous brethren used. Let’s take a look at the different parts that make up a high-tech and highly efficient killing tool.
Parts of Hunting Arrow
The modern hunting arrow is a marvelous combination of high-tech materials and advanced aerodynamic design. Gone are the days when primitive peoples used simple arrows of wood, bone, or reeds, though for thousands of years they served to bring home the game, and for modern purists they still do. With the advent of aluminum and fiberglass arrows in the 60’s and 70’s, technology began to make its mark, but the basic parts of an arrow remain the same.
The nock is a plastic tip with a slot located on the rear of the arrow. It snaps onto the bowstring at a point called the ‘nocking point’ and holds the arrow in the correct position.
Nocks come in several sizes to fit different strings, and having the wrong size can affect accuracy. A good nock fit will allow an arrow to hang from the bowstring pointing downward without falling off, although allowing the string to be rotated within the notch. In other words, with just enough grip on the string to hold it in place, but not too much.
Nocks are also sized to fit different arrow shaft sizes, and with different methods of attaching them to the arrow:
- Press Fit Nocks – The most common type used, these simply slide inside the hollow shaft and lock into place. Made to fit standard shaft inside diameters from .166” to .246”.
- Overnocks – As the name implies, these nocks slide tightly over the end of the shaft, and are available in many different sizes.
- Pin Nocks – These nocks fit over and lock onto a pin on the end of the shaft, and are of a universal fit. Mostly used by competition shooters.
- Conventional Nocks – These fit over shafts with a cone-shaped end, and are simply pressed into place, or glued.
All these types of nock can be easily replaced at home.
FletchingThese are the feathers or synthetic vanes on the rear of an arrow, usually numbering three but sometimes more. Two feathers will be the same color and one will have a different color, called the cock feather, which is the one that faces the hunter when shooting. They produce an aerodynamic drag and can impart a spin on an arrow, which improves flight stability and accuracy.
Arrow fletching can be made from natural feathers or synthetic materials, both of which have their pros and cons, and can be constructed in different lengths and shapes to alter the surface area of the vanes, and thus aerodynamic performance. Vanes are attached to the shaft in either a straight and parallel configuration, a helical pattern that wraps around the arrow, or an offset pattern that is a combination of both.
Arrows are usually purchased with the fletching already in place, but serious hunters can easily attach their own for more customized results using a fletching jig.
There are several factors to consider when selecting the proper arrow shaft, and using the wrong one can greatly affect accuracy and even be unsafe. Shafts can be constructed from fiberglass, wood, carbon, or aluminum, but the latter two materials are the most commonly used for compound bows and crossbows.
Factors to consider when choosing an arrow shaft:
- Weight – Lighter weights fly faster and with a flatter trajectory, but added weight increases penetration. The pros and cons of both are hotly debated. Both are used by hunters, depending on personal preference. A general rule is five to six grains for each pound a draw weight.
- Spine – The measure of the flexibility or stiffness of a shaft. Arrows flex in a series of oscillations when fired from a bow, and this can drastically affect accuracy. Correct shaft spine depends on the particular bow setup and determining it can be complicated. Manufacturers sell their arrows as appropriate for different draw weights, and this is sufficient for most hunters.
- Diameter – Many hunters believe that smaller diameter shafts impart greater kinetic energy upon impact and, being thinner, provide better penetration, but most use standard 5/16” and 9/32” shafts.
- Shaft Wall Thickness – Obviously this has a relation to both weight and spine.
Arrows must also be the right length for a particular bow draw weight. Technically an arrow’s length is measured according to the standards of the Archery Manufacturer’s Association (AMO), which designate that an arrow shall be measured from the bottom of the notch slot to the end of the shaft, without an insert or an arrowhead installed.
This is the measure used when ordering or purchasing new shafts. With the proper shaft length/draw length ratio, the end of the shaft should extend about 1 ¾” beyond the outer edge of the riser.
Shafts can be purchased in lengths that allow them to be custom cut to meet any AMO standard length, and this can be done at home. But it should be noted that carbon arrows should only be cut with an abrasive-wheel saw at high speeds, or a Dremel tool with a similar wheel.
Trying to do the job with a hacksaw or tube cutter will splinter the delicate fibers and damage, possibly ruin, the shaft. Since it usually costs nothing to have shafts professionally cut, this might be the best option for most.
Metal inserts, usually made of aluminum but sometimes brass, are installed into the front of a shaft, and incorporate a threaded aperture to allow different types of arrow tips, whether practice tips, broadheads, or other types of tips, to be quickly attached to the arrow.
These are available in several standard sizes to accommodate different shaft diameters. These are simply glued into the arrow shaft. If shafts have been cut to size at home, a tapering tool should be used to smooth the cut edges of the shaft.
Tips represent the business end of an arrow, and as far as the hunter is concerned, come in two basic types:
- Field Points – These are made for practice, shooting at a target or in the field. They are available in a bullet point, with a conical head, field point, which has a pointier head, and a grabbing point, which uses wire hooks to keep the arrow from being lost in the grass or heavy brush. They can be purchased in the same weights as the broadheads that are used for actual hunting, making practice more realistic. There is also a blunt point for hunting small game such as rabbits or squirrels.
- Broadheads – These are equipped with either three or four razor blades for hunting larger game, and come in fixed-blade types, which either glue directly to the shaft or are installed on a screw-in ferrule, removable-blade types, so that blades can be easily sharpened or replaced when dull or damaged, and expandable-blade types, which spring open upon impact.
There is a continuing debate on whether fixed or expandable-blade broadheads are more effective, although studies have shown that both types produce high deer recovery rates.
Expandable, or mechanical, broadheads have less drag in flight and aren’t as susceptible to aerodynamic factors, which increases accuracy. However, they can be fragile and don’t always deploy correctly.
Fixed-blade broadheads are stronger and more reliable simply because they are fixed in place, but they are more susceptible to drag and wind factors.
Arrows are very much like aircraft. Airplanes are designed to have specific characteristics depending on their intended use, and when you change one design factor to achieve specific performance, such as weight or external configuration, it’s always at the expense of other characteristics. For example, an aircraft can be designed to be fast and nimble, like a fighter, but it’s at the expense of fuel and cargo capacity, useful range, and stability.
Similarly, all the above factors and parts of an arrow come together to determine performance, and the bowhunter must consider them all together to achieve the most effective configuration for the bow setup and the intended mission